PSU miner Coal India (CIL) is trying afresh at underground (UG) mining, with an intention to renew present UG operations in the long run, and within the brief time period utilizing the punch entry technique to get beneath depleted opencast (OC) mines and extract extra reserves. Utilizing this technique for the primary time, CIL is nearly changing some OC mines to UG mines.
The corporate additionally plans to deploy 10 highwall machines in 4 OC mines this fiscal, with capex between ` 800-1,000 crore. The machines will extract the coal that an opencast mine leaves as non-extractable after reaching its final pit stage. A CIL government informed FE such coal can’t be extracted manually.
The projected manufacturing potential has been estimated at 5 million tonne a 12 months. A longwall mining undertaking entailing capex of `200 crore is already below approach in South Jap Coalfields (SECL). Three extra such initiatives will begin in Jap Coalfields ( ECL) this 12 months.
The manager stated contractors engaged for the initiatives will share the capex on a 50:50 foundation, and CIL should bear half the price. Longwall mining might additional result in making punch entry into coal-depleted opencast mines.
“Punch entry will truly make holes in an opencast mine and will create a horizontal pathway to entry underground coal within the opencast mine. Punch entry may very well be executed by means of a mixture of applied sciences, and CIL plans to establish and implement 5 such mines in a phased method until FY24,” he stated. The complete punch entry course of can be mechanised and there can be no miner going underground, making certain operational security.
Capex for the punch entry system might be estimated as and when the undertaking progresses and primarily based on the know-how used. However it’s prone to be on a sharing foundation, the chief stated.
The corporate had closed down all underground mines one after the other for techno-commercial unviability. However it’s exploring ramping up UG manufacturing fourfold to 100 million tonne (MT) by FY30 from 25.6 MT in FY22.
“UG output is environmentally clear, minimally invasive on land degradation and is society pleasant. Round 70% of the nation’s coal reserves are conducive for UG mining,” the CIL government stated, including the intention was to make UG manufacturing sizeably supplementary to the OC output. On the present fee, mineable coal reserves at present OC mines will slowly begin lowering.
Since nationalisation of mines in 1975, UG output has contracted 57.7% until FY22, whereas OC manufacturing has expanded 8.5 occasions. UG mines had been loss-incurring and had longer gestation intervals with lack of expert labour, unavailability of indigenous tools, and excessive departmental manufacturing price.
However UG manufacturing might now turn into techno-commercially viable with the supply of mass manufacturing applied sciences indigenously and well-trained expert labour. Outsourcing to contractors would scale down price of manufacturing, and the gestation interval is significantly decrease. CIL thus plans to steadily scale up using locked-up UG coal belongings, he stated.
Paste-fill know-how, one other surroundings pleasant frontier which includes high-speed stowing, might be appropriate with mass manufacturing applied sciences. As an alternative of standard sand stowing, it makes use of fly ash to fill the void created by extracting coal from UG mines. Such a system is in superior phases of implementation at ECL.
Amongst mass manufacturing applied sciences, CIL will introduce 50 steady miners by FY25 with peak manufacturing potential of 25 MT a 12 months. At present, 21 such machines are deployed at ECL, Central Coalfields and SECL, producing 9 MT a 12 months.
Two powered help longwall (PSLW) machines working at ECL and Bharat Coking Coal (BCCL) produced 1.58 MT in FY22, 40% increased than 1.13 MT produced in FY21. Two extra PSLWs with a complete capability of 4.5 MT a 12 months are quickly to be deployed at BCCL.